Turn off PACKET_DESTINATION_INFO for mingw-w64.

The CMSG_* macros used in CycloneDDS are not provided by mingw-w64-gcc (only WSA*).
Set the number of bytes received also for nonzero return from wsarecvmsg.
Closes eclipse-cyclonedds#2027

src/core/ddsi/src/ddsi_udp.c

@@ -49,6 +49,9 @@ DDSRT_STATIC_ASSERT (DDSI_LOCATOR_UDPv4MCGEN_INDEX_MASK_BITS <= 32 - UDP_MC_ADDR
 #  endif
 #endif
 #ifndef PACKET_DESTINATION_INFO
+#  if defined (__MINGW32__) && !defined (CMSG_SPACE)
+#    define PACKET_DESTINATION_INFO 0
+#  endif
 #  if defined CMSG_SPACE && (defined IP_PKTINFO || (DDSRT_HAVE_IPV6 && defined IPV6_PKTINFO))
 #    define PACKET_DESTINATION_INFO 1
 #  else

src/ddsrt/src/sockets/windows/socket.c

@@ -570,6 +570,7 @@ ddsrt_recvmsg(
     if (sockext->wsarecvmsg (sockext->sock, &wsamsg, &n, NULL, 0) != 0)
     {
       int err = WSAGetLastError();
+      *rcvd = (ssize_t) n;
       return recv_error_to_retcode(err);
     }
     else